Properties of concrete made with recycled coarse aggregate from waste brick

Abstract

Demolition of old buildings has produced a large amount of waste material. In this paper, experiments were performed to design the mix proportion of concrete made with recycled coarse aggregate from waste brick, and the workability, mechanical performance, and durability of the concrete with different contents of recycled coarse aggregate have also been investigated. Waste brick was used to replace natural aggregate after being treated, called recycled coarse aggregate (RA). Furthermore, fly ash was used as 0, 10%, 15%, and 20% by weight replacements of cement. Workability was evaluated through slump and cohesiveness testing, and results implied that the concrete samples showed good workability except the mix containing 40% RA. Mechanical performance testing indicated that addition of RA decreased compressive strength, and replacing up to 30% of natural aggregate with RA produced concrete samples which met the requirements of strength standards. Concrete with RA presented a little higher chloride ion penetration coefficient and carbonation depth than normal concrete due to the higher porosity. Pore structure testing also indicated that recycled aggregate from waste brick can increase the porosity of the concrete. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 1283–1289, 2014